Mail App on Windows 8.1 / Windows RT 8.1 will not sync to Outlook Email Account

The mail app on both our laptop and tablet will not sync to the Outlook email account.  The message states that it cannot sync.  When trying to sync manually we receive a popup message that the Outlook email account is not available.  We can log into the Outlook account via Internet Explorer without any difficulty, but cannot get the emails on the Mail Apps.  We have tried to remove the Outlook email account from the Mail and then set it back up again, but when we do so we get the message that the account is already set up.  Any suggestions?